Thank you Jose. It is clearly 1.81 as suggested by Raimey



1.81 grams = 27.93 grains.
28 grains of a "33 grain" Bulk powder; Walsrode Gray, "E.C." No. 3, or Mullerite No. 2 = 2 1/2 Dram Equivalent

1 oz. 2 1/2 Dr. Eq. would be the standard c. 1900 U.S. 16g load

BTW: I was in Queretaro 2 summers ago visiting my father in Juriquilla.